Influence of genotype on phosphate uptake and utilization efficiencies in spring barley.

摘要

In pot experiments, 24 high-yielding spring barley cultivars were grown until maturity under P stress (50% of the maximum yield) or optimum P, or were grown until tillering under low or high P supply. At maturity, the range between cultivars with the highest and the lowest values were 30% for total dry matter yield (grain and straw), 28% for grain yield, 24% for P uptake efficiency (P in grain and straw), 26% for P concentration in grains and 24% for P utilization efficiency quotient (PEQ, g graindry matter per mg P in shoots). Grain yield was correlated with P uptake per plant. There was only a weak relationship between P uptake and PEQ. Therefore, a combination of high uptake efficiency and high PEQ in a cultivar may be possible. At tillering,the cultivars showed a significant variability in shoot biomass, P concentration, P removal, P influx, activity of acid phosphatases (Pase) and root length. The ranking of the cultivars, however, was very different at the two P levels, but the root length and the Pase activity were more influenced by genotype than by the P supply. As the relationships between grain yield, P removal, PEQ and the characters of the young plants cultivated under P stress were very weak, selection for P efficiency at the stage of tillering cannot be recommended.